Sound-regenerating machine.



Patented July 2, 1918'.

5 SHEETS-FSHEET I.

M. c. HoPKms. SOUND REGENEHATING MACHINE. APPLICATION FILED JULYH, v|913- RENEVVIED MAR. `22. WIB.

\-l QQ M. C. HOPKINS.

SUND HEGENEHATING MACHINE. APPLICATION mm Junin-|913. RENEWED MAH. 22, 1,271,527.

Patented July 2, 1918.

5 SHEETS-SHEET 2.

1 l .NW s s s m u L O JV lu .m WKN r 1 A i.; //f. 5.1? A novffvwl 5:? l

WIIVESSES m14. 777. l M

M. C. HOPKINS.

SOUND REGENEHATING MACHINE.

APPLICATION FILED IULYN. Isls. RENEwED MAL 2z. 191s. 1,271,527.

Patented July 2, 1918.

5 SHEETS-SHEET 3.

mvfnro DQ k Marca; 6' /ro/ns er p' if v m'rormsw` WITNESSES 777, L ma M. C. HOPKINS.

SOUND HEGENERATING MACHINE. APPLICATION minlnv/14.1913. RENEWED MAR. 22. ma. 1,271,527.

Patented July 2, 1918.

5 SHEETS-SHEET 4.

ATTORNEYS WTNESSES wfm@ Q f. w

NI. C. HOPKINS.

SOUND REGENERATING MACHINE.

APPLlcMIoN F1LED1uLY14.1913. RENcwED MAH. 22. ma.

1 ,27 1,527. Patented July 2, 1918.

5 SgEETS--SHEET 5.

Q WITNESSES INVENTUMA TTORN E YS nsncus c. HOPKINS, or JERSEY CITY, NEW

ums, 'ro LEx'rornoNE CORPORATION,

- DELAWARE.

JERSEY, ASSIGNOR, BY MESNE ASSIGN- OF NEW YORK,A N. Y., A CORPORATION 0F SOUND-BEGENEBATING MACHINE.

Speoioation of Letters Patent.

Patented July 2, 1918.

Application led July 14, 1918, Serial 17a-778,826. Renewed Hal-ch 22, 1918. Serial No. 224,048.

To all whom t may concern:

Be it known-that I, MARCUS C. HOPKINS, a citizen of the United States, residing at No. 2859 Boulevard, Jersey City, county of Hudson, and State of New Jersey, have iny vented certain new and useful Improvements in Sound-Regeneratng Maohines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. i

This invention relates to instruments which .reproduce sounds, such as the talking machine and the phonograph, and is particularly directed to the attainment of a direct propagation in free air from a record of selfsustaining sound waves substantially corresponding to the Original recorded sounds in intensity or am litude as lwell as in pitch` I herein term a regenerator, and, this device in the phonograph and talking machine comprises the reproducer together .with the trumpet. The reproducerfalone is 1ncapable of generating such sound waves in' air, and the violent air disturbances which are produced by its diaphragm, and which issue through its mouth piece, are almost immediately dissipated in heat or in waves, whicharenot heard at any considerable distance if the horn be removed,

In the case of the reproducen all of the energy received from the record issues from its mouth as relatively violent disturbances, which are impressed upon a very small amount of free air, quite incapable of conf ducting such disturbances without transformation losses, and therefore the trumpet is resorted to to resist transformation into heat andto control the lateral forni of the wave during a progressive spreading action, wh1ch is accompanied by a lessening of the violence of the disturbances, until a wave front of great area is attained having a movementv transformer.

appropriate to the sound conductivity of air. In this way it has been found practicable to transform a satisfactory part of the energy obtained from a moving record, into self-sustaining sound waves in air, but in every instance this method has been accompanied by distortions of the true recorded sounds in the reproducer, and more particularly in the trumpet, giving rise to those characteristic sounds, known as phonograph and horn sounds. These distortions of the true sounds are in a measure impressed upon the record in its making, but are more noticeablein the reproduction where a suppression of character and overtones, the loss of timbre in instruments and the voice, and the accentuation of notesof certain pitch, so change the recorded number that a tion is not obtained. a

It is an object of the present invention to regenerate the recorded sounds direetlyfrom the record, without the interposition Vof a confined body of air and without the employmcntV of a restrictive transformer, such as a horn.

'lhe Sound regenerator, in the case of the presentinvention, comprises a tympa num of relatively great. area freely exposed to unconfined air, in which the sounds are to be propagated, and'a mechanical transmis sion which faithfully transmits the vibra-` tions produced by the record, to the tympanum, 1n such manner that the tympanum excites directly in the free air surrounding it sound waves of an intensity or amplitude substantially corresponding to the original recorded sound waves. In other words, the

Aoiiggginal `soundsare directly regenerated by the `vibrating ytympanum without the interpositlon of a restrictivefor sound 'modifying The invention consists in providing a ca able of respondin to the high fre uenc D g l y vibrations employed 1n the reproduction of Isounds, and of imparting these vibrations to a large body of air; in providing a suitable mounting for this tympanum to permit it to exercise its function; and in providing a vibration transmission for receivin the vibi'atory movement. from the record and transmitting this movement to the tympanum, without change 'of character and apr which has specifically pointed out in 4ally preciable loss of ener The invention also com rehends certain combinations of parts an details of construction and location hereinafter particularl described t e appended aims.

I have illustrated in the accompanying drawings a sound reproducing machine embodying the several novel features of the invention as the may be ein loyed in reerating soun s from reoor s made with either laterally or vertically sinuous grooves.

In the drawings,`

Figure 1 is a plan view of the machine with the cover raised.

F' 2 is a vertical section on line 2-2 of F l, with cover and transmission arm Fig. 3 is a vertical section on line 3 3 of Fi 1 with cover closed. lig. 4 is a vertical'section on line 2-72 of ig. 1 with, cover closed and transmis sion arm in playing position.

Fig.v 5 is a longitudinal section through the transmission arm on line 5 -5 of Fig: 4. Fig. 6 is a vertical longitudinal section through the transmission arm on line of Fig. 5;

Fig. 7 of Fig. 6.

Fig. 8 is an end view of the transmission arm.

Fig. 9 is a. cross-section on line 9-9 of Fi 5, and

dii 10 is a viewsimilar Fig.8 of a mo ded arrangement for vertically sinuous reco s Referring to the drawings, the illustrated machine is mounted within a cabinet having aV deck A upon which the motor and soun regenerator are suilplorted. Side walls B downwardly exten g from the edges of the deck A are referably apertured on all is a vertical section on line 7-7 sides and rovi ed with open work grilles C which al ord substantial y uninterrupted air paths for the sound waves from the interior of the cab t in all directions laterto the surroundin atmosphere. In the machine shown the cabinet is bottomless and D at its four corners. The motor may be of an suitable type, that shown having a frame spring drums e, winding gear e', spiral drive gear e", high pitch spiral table shaft e" and governor 6". The frame E of the motor is secured against the under side of the dec depending therefromand the table shaft projects upwardly through the deck A and carries the circular record ,table F above the deck. The motor frame E is preferably insulated from the deck A by rubber washers not shown.

The soundregenerator has a right-angled tubular suport G, the vertical arm g of iametrically opposite conical deprovided with legs screws ytwo rubber or felt rin invasa? pressions g' which are en ged by pointed y h which pro'ect ingvtardly from and are threaded throug a ring It of larger in ternal diameter than the external diameter of the vertical arm g of the right-angled support G. The pointed screws h engage the depressions g formin perpendicular to the right-angled axis the arm g lane,

support G about which can swingl in a vertical the vertical arm g t e while being inclin d within the ring h. The ring h comprises the ring h proper and an annular retamin plate h .screwed upon the lower face of e ring h, an annular groove at the imction ofthe ring h and plate h receiv. ing the inner edge of a holding plate H in such manner right-angled support G about 'a vertical axis in the holdin The holding plate H late H. is clampe tween i, i', the lower ring s" resting upon theeck A. A ring I is placed upon the top of*` the u per ring i and screws z" have their hea s seated in the ring I and are screwed down into the deck A. The ring H and the rubber or felt rings i and z" have large holes through which the screws i pass, so that these screws do not come into contact with the ring H and the right-an led sup ort G is therefore entirely insulat from t e deck A by the rubber or felt rin The vertical arm g of the right-angl through an aperture in the deck A at a point near the periphe of the record table F. A conical spider shown as having three arms hasvits hub j fitted to the lower extremit of the vertical arm g of the rightangle support G and is secured thereon by a set screw j. 'lio the ends of the arms of the spider J is secured b screws an annulus consisting of two pon crous rings of metal, these two rings being clamped together by screws k spaced at short intervals.

wo of the three arms of the said spider are screwed tightl to thevrings K, K and the third is as tly secured tc said rings but b adjustab e in suc manner that the rings K, K can be secured at varyin distances from the foot of this third leg, t ere being sui'licient s ring in the spider egs to permit of an a justment at this po' t of one-quarter of an inch or so, if desired. It will be seen that owing to the proximity of the mounting of the screws k', k arrangedl l a horizontal axis i the horizontal arm g" of that the ring h andihe may be turned vertical arm g of` the right-angled support G to the edge of the record table F, the s ider J and the rings t e record table and permit of a very com pact arrangement of the working parts within the cabinet.

A tympaiium L of light rial has an annular plane tion l, the outer edge of w vibratile mateeripheral porich peripheral K, K will underhe c portion or supporting rim l is tightly grip ed and rigidly supported between the pon erous rings K, K', and a central coni,

cal portion Z rising from the inner edge of tht` Aannular plane peripheral portion. VIf satisfactory regeneration of sounds from a record is to be had, the whole diameter of the tympanum, that is the diameter of the aperture in the rings K, K', should exceed nine inches in order that the conditions shalldiameter of the circular aperture in the slip-` porting rin K, K. The altitude of the conical portion l of the tympanum should be at least one-quarter of the diameter of its base. It is, of course, possible to make some variation from the approximate sizes given without materially altering the result, but if the tympanum is made as shown in the drawings, -any great variation from these proportions will be found to affect the character of the reproduction. portaiice that the tympanum be made of crisp, strong material, havin considerable rigidity within itself, and it is also of vital importance that the tympanum as a whole be extremely light and have as little inertia as possible without a weakening effect. The tyiiipanuin is shown of. conical form with a smooth surface, and this has been found to be very satisfactory. The conical shape is given the tyiiipauuni so that Shocks' or vibrations impressed upon the apex of the cone ina direction toward its base will movethe whole cone bodily, the strains being impart-A ed edgewise of the material and no wave motions being set up in the thin material of the cone. The curvature of the walls of the cone preclude the setting up of waves in the material and the intended object, a simultaneous movement of the whole conical article for the purpose. It is possible thatl when the tyiiipanuni is provided with corrugations as just suggested, some variation from the proportions above given may be found possible, and perhaps advisable, but such variations from the proportions iven will not be great. The tympanum sliould It is of vital iin-A preferably he constructed of a colloidal substance and should be from 3 to 20 thousandths of an inch in thickness according to the crispness or still' character of the material used. Compressed fibrous material, such as hot pressed paper or ber, has been found to act satisfactorily. It will be noted that the arms of the spider J incline downwardly to correspond with the conical shape of the tympanum L and that the' apex of t l e conical portion of the tynipanum is point! ed upwardly toward the deck A of the cabinet, and that the concaveside of the tympanum is open to the surrounding atmosphere through the open-bottom of the cabinet, no obstructions being presented to the sound waves issuing from theconcave surface of the tympanum.

A cap M is secured to the apex of the conical portion l of the tympanum L, and

this cap should be of more rigid construction than the remainder of the tym anum an'd should preferably be three-eig ths of an inch or more in diameter. I prefer to make the cap M of metal, extremely light but very rigid, and iii the form of two concs m2, fm.' screwed tightly together upon opposite sides of-the tympanum and gripping with their edges the material of the conical portion of the tympanum. In' order that a tight and 05 positive application of the cones forming 4the cap M to the conical portionof the tympanum may be had, it is preferable to forni the cone m of lesser angle than the conical portion of the tympanum, and the cone m of greater angle than the conical portion of thetympanum in which case their edges willsecurely grip the tympanum ma terial when they are secured together. The

cap M is applied to the tympanum toieceive l the shocks which are to be applied to the tympanum as a whole, and convey them to suficient of the material of the tympanum to insure the movement of the tympanum as a whole. This will be better understood when it is considered that if the shock were applied to paper or hard rub'ber at a single' small oint, the inertia of the tyinpanum as a who e would be sufficient to resist the attack-and the material wouldbe distorted 115 or dented at that point, the effect of the shock upon the tympanum as whole being entirely lost. The cap M being of hard ma terial such as metal will-resist the bendin action and distribute the shock .to so muc 130 of the surface of the material of the tym# panum as is capable of successfully resisting the shock, and it will then be transmitted to the tympanum as a whole. The plane peripheral portion lof thc tympanum maiiitains the place of the conical active'portion of the tympanumand yields suiciently to permit of the requiredmotion of the conical portion, resisting, however, displacement of the conical portion in just that degree necessary to maintain the form and neutral o- `sition of the active conical portion. ere the `plane peripheral portion Z of considerably reater width or markedly narrower than escribed, its function would be destroyed to a degree corresponding to the remoteness of the departure from the approximate proportion given and the-effective portion of the conical portion of the tympanum would bepro ortionately lessened. i

In the tubu ar arm g of the transmission support G are located two ponderou's members or weights N and N. These members N and N are shwn as insulated from the wall of the arm g by a tube o of insulating material, such as soft rubber or felt. One at least of the ponderous members N and N must be movable relatively tothe other and therefore it cannot be rigidly secured to the support G, and the insulating material becomes necessary to avoid rattling. I preferably insulate both of the ponderous members or weights N, N from the wall of the transmission support G, Pins P` projecting from the ponder-ous .member N, and sliding in liolesin the other ponderousmeinber N', `act as guides and prevent disalinementand angular displacement of the movable onderous member. Knife edge fulcro n an n are secured in and roject from the ends of the ponderous mem ers N and N', and in the form of the device shown in Figs. 1 to 9 the fulcra a are arranged horizontally and the fulcra n are arranged vertically. A lever Q'is mountedonthe fulcro n' and is capable of movement upon a vertical axis. A style holder g projects from the lever Q downwardly at an incline s0 that the point of a style g' held in the style holder is considerabl removed from the axis of the lever Q an movement given the style by the record will elect an oscillation o the lever Q about its vertical axis upon the fulcra n. The lever Q has arms g and projecting from opposite sides thereof, t ie arm q benear the top .of the lever Q and the arm being near the bottom of said lever.

A gfhe reason for this arrangementof the arms upon the lever will presently appear.

A lever R is mounted upon the fulcra n and oscillates upon a horizontal axis. This lever has arms r and r' extending upwardly and downwardly from its opposite sides, the arm r projecting from a point near one end of the lever R', and the arm 'r' projecting from a point near the other end o the lever R. It will now be seenthat a point upon the arm r of the lever R is o posits a similar point on the arm g" of t e lever Q and these two points are connected by rod link S'. It will also be seen that a point upon the arm i" of the lever R is opposite a point` upon the arm 9'" of the lever Q, and two points` are connected by a rod link S'. The rod links S` and S' have eye-ends ar- `secured a rod V which extends downwardly these4 ranged in planes removed 90 from one another, a'nd these eye-ends s are engaged by )ivot screws s' upon the arms of the levers il and R. A arallelogram is formed by the levers Q and and the rod links S and S, and in the form just described, which is adapted for a laterally sinuous groove in the record, oscillation of the lever Q about a vertical axis will produce like oscillations of the lever R about a horizontal axis. Springs T preferably mounted upon the pins P press the ponderous members N and N a art forcing the knife edge fulcra n an n tightly against the levers R and Q., and put the parallelogram of levers and links under tension, precluding any rattle or loosencss of the levers upon the fulcra or of the eyeends of the links upon their pivot screws. and as the movable ponderous member of the combination is insulated from the transmission support G, no rattle or displacementI of the parts can take place when the record roove oscillates the lever Q, but such oscilation will be faithfully transmitted to the lever R. The ponderous members N and N have clearance holes s for the rod links S and S. f

Au arm U pro'ects from the central portion of the level' and to its end is rigidly through the interior of the arm g of the transmission support G, its lower end being rigidly secured to the ca M of the tympaniiin. The rod V is nic ed or thinned at i' close to the arm U of the lever R to permit of n slight springiii action which compensafes for the very s ight angular motion of thc arm U when the lever R is oscillated. It will now be seen that the oscillation of the lever R- about its horizontal axis im- 108 parted to it from the lever Q, will effect an endwise vibration of the rod 'V which is directly impressed upon the tympanum L. A cap lV closes the opening at the angle of the transmission support G and the removal of 110 this ,cap gives access to the working parts of the rear end of the transmission.

It will be noted that the distance between the point of the style g and the axis of the lever Q is greater than the length of the arm small movement of the tympanum, its large area enables it to move a large body of, air, so as to obtain sound waves of large volume and at cari-yin power.V

W'Egi a 'verticay sinuoiis record is em- 180 ployed the lever Q is mounted to oscillate about a horizontal axis, as shown in Fig. 10, no change in the lever R being required.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is

1. In a machine for directly regenerating sound from a record of the same, a vibratile conical tympanum of large area rigidly supported at its peripher and freely exposed to uuconfined air, andya mechanical transmission through which the vibrations produced by the record are transmitted to the tympanum, the tympanum being of Sullicient area to impart to the surrounding free air, when the tympanum is so vibrated, sound waves substantially corresponding in intensit to the recorded sound waves; substantial y .as described.

2. In a machine for directly regenerating sound from a record of the same, a vibratile conical tympanum of large area rigidly supported at its periphery'and freely exposed to unconfined air, a mechanical transmission through which the vibrations produced by the record are transmitted to the tympanum, the tympanum being of suicient n area to impart to the surrounding free air,

' open-.work cabinet inclosin when the tympanum is so vibrated, sound waves substantiall corresponding in intensity to the `recordladrsound waves, and an the tympanum but affording substantially ree access of the described;

3.` Inadirect sound. regenerating machine,

surrounding air thereto; substantially as l the combination of a. record holder, a transmission-'support mounted to swing over said reco-rd"h`elde1, .and a tympanum carried by said. Ysupport; and extending under said record holder; substantially as described.

j4. In a direct sound regeneratin machine,

the combination with a record ho der, of a transmission support mountedV to swing about vertical and horizontal axes, said support having an arm extended to move above and across said record holder and adapted to carry a stylus, the sup ort having a second armhaving a free en and a tympanum carried at the free end of said second .arm with its axis at an angle to said first arm; substantially as described.

5. In a sound regenerating machine, a vibration transmission comprising two ponderous vmembers, fulcra carried by said members, an articulateparallelogram having opposite sides mounted Aon -said fulcra and means exerting pressure upon lsaid ponderous members to place said parallelogram under tension; substantially as de-V scribed. v

6. In a sound regenerating machine, a. vibration t dei-ous members, fulcra carried bysaid inembers, an articulate parallelogram of nouransmission ,comprising two pon-- extensible links and non-flexible levers, the levers of said parallelogram being mounted on said fulcra,.and'means exerting pressure upon said ponderous members to place said parallelogriun under tension; substantially as described.

In a machine for directly regenerating sound from a record of the same, a tympanum support having a circular aperture, alight vibratile tympanum of long area having its outer edge rigidly mounted in said support, said tynipanum being sha ed to provide an annular sustaining rim adjacent said support, and a conical portion springing from the inner edge of 'said annular rim, a cap of non-vibratile material rigidly secured Vto the apex of said conical portion of said tympanum, and afmechanical transmission through which the vibrations produced by the record are transmitted to the tympanum, the tympanum being of suicient area to impart to the surrounding free air,when the tympanum is so vibrated, sound waves substantially corresponding in intensity to the recorded sound waves; sub.

stantially as described. 4

8; In a machine for directly regenerating sound from a record of the same, a pon-- `mechanical transmission through which the vibrations produced by the record are transmitted to the tympanum, the tympanum being of suiiicient area to impart to the surrounding free air, when the tympaiium is so vibrated, sound waves substantially corresponding 'in intensity to the recorded sound waves; substantially as described.

9. In a machine for directly regenerating `sound rom'a record ofthe same, a ponderous tympanum 4support having a circular aperture, 'a light vibratile tympanuin exceeding nine inches in diameter, havingits outer edge rigidly mounted on said sup- =port, said tympanum being shaped to pro- 'vide an annular rim adjacent said support,

and a conical portion springing from the I, inner edge of said annular rim, a cap of non-vibratile material rigidly secured to the apex of said conical ortion of saidtympanum, .and a mee anical transmission through which the vibrations produced by the record are transmitted to thetympanum, whereby the tympanumlimp'arts to the sur rounding free air soundwavessubstantially corresponding in intensity tothe recorded `sound lwaves; substantiallyv as described. .Y 10. In a machine for directly regenerating soundfrom a record of the same, a ponderous` tympanuni support .having a circular aperture exceeding nine inches in diameter, a light vibratile tympanum mounted in said aperture and having, its outer edge rigidly secured upon said sup ort, said tympanum being shaped to provi e an annular rim adjacent sai'd support, and a conical portion springing from the inner ed e of said annular rim, the diameter of t e base of said conical ortion being not less than eighttenths o the diameter of the said circular a rture in said su port, a cap of non-vibratile material rigid y secured to the apex of said conical portion of said tynipanuin, and a mechanical transmission through which the vibrations reduced by the record are transmitted to t e tympanuni, the tympanum being of sufficient area to impart to the surrounding free air, when the tympanuin is so vibrated, sound waves substantially corresponding in intensity to the recorded sound waves; substantially as described.

11. In a machine for directly regenerating sound from a record of the same, a ponderous tympanum su port having a circular aperture, ali ht vi ratile tympanum of long area mounte in said aperture, and having its outer edge rigidly secured to said support, said tympanum being shaped to provide an annular rim adjacent said support, the outer diameter of said rim exceeding nine inches, and a conical rtion springing from the inner edge of sai annular rim, the 'altitude of said conical portion being substantially one fourth of the diameter of its base, a cap of non-vibratile materialy rigidly secured to the apex of said conical portion of said tympanum, and a mechanical transmission through which the vibrations produced by the record are transmitted to the tympanum, the tympanum being of sufficient area to impart to the surroun ing free air, when the tympanum is so vibrated, sound waves substantially corres ending in intensity to the recorded soun waves; substantially as described.

12. In a machine for directly regenerating sound from a record of the saine, a ponderous tympanum support having a circular aperture exceeding nine inches in diameter, a light vibratile tympanum mounted in said aperture, and having its outer edge rigidly secured to said support, said tympanum being shaped to provide an annular rim adjacent said support and a conical portion springing from the inner edge of said annular rim, the diameter of the base of said conical ortion being not less than eighttenths o the diameter oflsaid circular aperture in said sup ort, and the altitude of said conical portion ing substantially onequar-y ter of the diameter of its base, a cap of nonvibratile material rigidly secured to the apex of said conical and a mechanical transmission t rough which the vibrations produced by' the record and levers, the

rtioii of said tym anum,

are transmitted to the tympanum, whereby the tympanum imparts to the surrounding free air sound waves substantially corresponding in intensity to the recorded sound waves; substantially as described.

13. In a sound regenerating machine, a vibration transmission comprising two ponderous members, fulcra carried by said mem bers, an articulate parallelogram of links and levers, the levers of said parallelogram mounted upon said fulcra, pressure exertin means acting between said members an tendin tlirou'gh said fulcra to hold said paralle ograiii` under tension, and a style holder carried by one of said levers; substantially as described. f

14. In a sound regenerating machine, a vibration transmission comprising two ponderous members, guides for maintaining the relatievp positions ot said members, fulcra carri by said members, an 'articulate parallelogram of links and levers, the levers of said parallelogram mounted upon said fulcra, pressure exerting means acting between said members and tending through said fulcra to hold said arallelo am under tension, and a style ho der carried by one of said levers; substantially as described.

15. In a sound regenerating machine, a vibration transmission comprising two ponderous members, guides for maintaining they levers; substantially as described.

.16. In a sound regenerating machine, a vibration transmission comprising two ponderous members, a vertical fulcrum on one of said members, a horizontal fulcrum on the other of said members,'an articulate paral lelogramof links and levers, the levers of said parallelogram mounted upon said fulcra,land pressure exerting means acting between said members and tending throu h said fulcra to hold said parallelograni un er tension; substantially as described.

17. In a sound regenerating machine, 'a vibration transmission comprising two pendereus members fulcra carried by said mera bers, an articuiate parallelogram of links levers of said parallelograni mounted upon said fuicra, pressure exerting means acting between said members an tending through said fulcra to hold said parallelogram under tension, a style-holder carried by one of said levers, a direct sound regenerating tympanum connected to another of said levers and a pvoted support iis substantially as described.

mounte between sai( -untensioned tympanum, a

18.. In a sound regenerating machine, a vibration transmission comprising a su port, two ponderous members carried ,'y said support, one of said nicmbersgbeing movable upon said support, insulating m'aterial between said movable member and said support, fulcra carried by said inembers, an articulate parallelogram of links and levers, said levers being mounted on said fulcra and pressure exerting means actin members and tending throng i said fulcra to hold said parallelogram under tension; substantially as described.

' 19. In a direct sound regenerating machine, the eombination'of'a bottomless cabinet having apertureson all sides and a horizent-al iartition therein, a record holder u on and above ,said partition, a s motor for riving said record holder, -a right angled transmission support mounted to swing upon horizontal and vertical axes upon said partition adjacent the periphery of said record holder, one arm of 'said support adapted to be swung over said record holder, andthe other` arm of .said support .extending downwardly through said partitiom-a'vibiiation transmission mounted within and insulated said transmission support and comprising two ponderous members carry-' ing fiilcra, a parallelogram of links. and 1evers, said levers mounted upon said fulcra, pressure exerting means acting between saidmembers 'and tending through said fulcra to hold said parallelogram under tension, a style-holder carried by 'one of said levers at' theouter end of said transmission support, a spider mounted upon said transmission support .below 4said partition, a ponderous tympaniim support carried by said spider, a direct' sound regenerating tympamim mounted upon said ponderous tympanum support,'said tympanum being of light vibratile material and having a conical form throughout the greater part of its area and a positive connection between the4 apex of the conical portion of said tympanum and the inner end of theparallelogram of the said vibration transmission substanti.ally as described.

20. In a sound regenerating machine, 'a tympanum a vibration transmission tensioned in t erdrection `of its vibration independently of the tym a'nllm and connected therewith, and a style holder connected with said transmission.

21. Inja sound regenerating machine, an

vi ration transmissiontensioned in the direction of its vibrationr and connected-'with said tym. panum, and a style holder connectedwth said transmission.

22. In a sound regenerating ,.macliine, a

tympanuni, an oscillatory transmission meniber A connected therewith, a style holder for oscillating the transnussion member, land to the said element.

bei' connected therewith, a st le'holder for v oscillating said member, an means inde-A pendent of the tympanum for ieldingly im.-

24. In a sound regenerating machine, nn untensioncd tyin anum, a transmission m'cm-v ber connected t ierewith and adapted for oscillation, a style holder for oscillating said member, and means for' imparting a tension.

t0. said member inthe direction of its oscill .parting a tension .to ,said'mem r in the direction of its oscillatory movement.

sion means connecting the style and tympaniim and. having ,means for imparting vibrations to the tympanumV hav-in no greater length than the vibrations o the style, the tension of said transmission being in the direction of its vibrations and indel pendent of the tympanum.

27. In a sound regenerating machine, a tympanum having avibratile area of sufficient size to effect, without amplification, the regeneration from a record' of sound waves of relatively large ,volume and carrying power, and tensioned vibration transmitting means connected to the tympanum and` adapted to be actuated by a st le,the tension of e transmission being in e direction of its vibration and not extending to the tympanum.

28. In a sound regenerating machine, a

tensioned A vibration transmission, a styleholder upon one end ofsaid transmission and an untensioned tympanum connected with the o'ppositeend` of said transmission, the

tension of the transmission being in the direction of its vibration; substantially as described.

' 29. In a sound-regenerating machine, a

vvibratile conical tympanum of large area rigidly supported at ,its eriphery 'and freely exposed to unconfin vibrated element, and vibration transmission means connecting said element and said tympanum and arranged to impart to the tymcplanum vibrations which are relatively shorterthan the vibrations imparted iis 12o.' air, a soindv30. In a sound-regenerating machine, a i

vibratile conical tynipainim rigidly supported at its periphery and freely exposed t0 unconfined sir, a sound-vibrated element, and vibration transmission means connectinslnd element and said tyl'npsnum arranged impart to the tympanum vibrations which are relativel7 much shorter than 'the vibrations impante tothe said element; the tympanum hhving an area sulcently large to eiect, without gmpliication, sound waves of large volume and carrying power` 31. In n sound-regenerating machine, :L vibratile conical tympanum of large area, rigidly supported at its periphery and freely exposed to unconned air, a sound-vibrated element und -tensioned transmission' means connecting said element and said tympanum 1f,

.and arranged to impart. to the tympnnum MARCUS C. HOPKINS.

Witnesses:

M. A. BILL, Leon W. RosEN'rHAL.

i It is hereby oertied that in Letters Patent No. 11,27l,527, granted July 2, 1918, upon the application of Marcus C. Hopkins, of Jersey City New Jersey, for an improvement in "Sound-Regenerat ng Machines, errors appear io the printed speci- 'qaton requiring corretion an'followszlage -lflne 25, for the word "mgaphone read megaphmte; page 5, lines 75 and 95, clairns 7 and 8, and page 6, line 25, claim 1l, for the word long read large; and that the said Letters Patent should be with these corrections therein that the same may conform to the' record of the cese in the Potent ffioe.

Signed and sealed this 28th dey of September, A. D., 1920.

M; H. coULs'roN,

Acting Oommn'oner Patente i [am] 

